Fig. 4.

Transformation by (R)-2-HG is reversible. (A) Proliferation of TF-1 cells under cytokine-poor conditions after being passaged 4 times in the presence of DMSO or 250 μM TFMB-(R)-2-HG. At the time of GM-CSF withdrawal TFMB-(R)-2-HG was either maintained [continuous (R)] or removed [out of (R) on day 0]. (B) Proliferation of TF-1 cells under cytokine-poor conditions after being passaged 20 times in the presence of DMSO or 250 μM TFMB-(R)-2-HG and then undergoing wash-out of TFMB-(R)-2-HG for the periods indicated. (C) Differentiation of TF-1 cells after being passaged 20 times in the presence of 500 μM TFMB-(R)-2-HG or DMSO. At the time of EPO administration TFMB-(R)-2-HG was either maintained [in (R)] or removed [out of (R) on day 0]. (D-F) Differentiation of TF-1 cells (D and E) and SCF ER-Hoxb8 cells (F) transformed with IDH1 R132H (D and F) or TFMB-(R)-2-HG (E) and then passaged 5 times in the presence of DMSO or a small molecule inhibitor of IDH1 R132H (1 μM). (G and H) Proliferation under cytokine-poor conditions of early-passage (p15) TF-1 cells transformed with IDH1 R132H (G) or TFMB-(R)-2-HG (H) and then passaged 5 times in the presence of DMSO or a small molecule inhibitor of IDH1 R132H (1 μM) prior to growth factor withdrawal. Growth curves show mean values of duplicate experiments ± SD. FACS plots shown are representative results of three independent experiments.